1. Field of the Invention
The present invention relates to apparatus for use in treatment of the human body. More particularly, the present invention relates to an elongated device which may be a single catheter assembly or a multiple component catheter assembly and which is suitable for use through percutaneous or other access, for endoscopic procedures, or for intraoperative use in either open or limited access surgical procedures. Still more particularly, the present invention relates to an elongated device in the form of a waterjet throebectomy catheter, hereinafter termed crossflow thrombectomy catheter, for fragmentation and removal of thrombus or other unwanted material from is blood vessels or body cavities that uses high velocity saline (or other suitable fluid) jets to macerate the thrombus or other unwanted material. The elongated device bears certain similarities to known waterjet thrombectomy catheter constructions but differs therefrom in several material respects, a major distinction being in the provision of means which produce crossflow jets to create a recirculation flow pattern optimized for clearing a large cross section of mural thrombus or other similar material, the name crossflow thrombectomy catheter deriving from this major distinction. Further, the present invention also relates to a system constituted either by the combination of the elongated device with both pressurized fluid source n and exhaust regulation means or by the combination of the elongated device with only pressurized fluid source means.
2. Description of the Prior Art
Waterjet thrombectomy catheters have been described in which a distal-to-proximal-directed waterjet(s) flow(s) past a window, orifice or gap at the distal end of the catheter, reentering the catheter and pushing flow through an evacuation lumen. When placed in a vessel containing thrombus and activated, the high velocity jet(s) will entrain surrounding fluid and thrombus into the window, orifice or gap region, where the high shear forces of the jet(s) will macerate the thrombus. The macerated particles will be removed from the body by the pressure generated on the distal end of the evacuation lumen by the impingement of the high velocity waterjet(s).
A limitation of these waterjet thrombectomy catheters has been the inability to remove organized, wall-adherent thrombus from large vessels. In accordance with the present invention, a cross stream thrombectomy catheter is described which overcomes this limitation by optimizing the recirculation pattern at the tip of the catheter to increase the drag force exerted on the mural thrombus to break it free from the vessel wall and allow it to be removed by the catheter.